The hitmaker was asked by the 'Yeezus' rapper to perform the night before the superstar couple's ceremony when they held a bash in Paris in May, and she revealed the couple "seemed very happy" on their big day.
She told the Sunday Times Magazine: "It was beautiful, just being there."
"They seemed very happy ... Kanye told me he really liked where I was coming from, visually and sonically."
Meanwhile, the star was forced to deny rumours she was paid up to $2.8 million to perform at Kim and Kanye's wedding.
She previously said: "I would never let a friend pay me to sing at a wedding, that would be crazy ... I'll do a normal wedding for free like I did this one!"